I. Field
The following description relates generally to wireless communications systems, and more particularly to facilitating dynamic selection of a physical random access channel (PRACH) configuration to be employed during a random access procedure.
II. Background
Wireless communication systems are widely deployed to provide various types of communication content such as voice and data. Typical wireless communication systems may be multiple-access systems capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). Examples of such multiple-access systems may include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, and the like. Additionally, the systems can conform to specifications such as third generation partnership project (3GPP), 3GPP2, High Speed Packet Access (HSPA), High Speed Downlink Packet Access (HSDPA), High Speed Uplink Packet Access (HSUPA), 3GPP long-term evolution (LTE), LTE Advanced (LTE-A), etc.
Generally, wireless multiple-access communication systems may simultaneously support communication for multiple mobile devices. Each mobile device may communicate with one or more base stations via transmissions on forward and reverse links. The forward link (or downlink) refers to the communication link from base stations to mobile devices, and the reverse link (or uplink) refers to the communication link from mobile devices to base stations. Wireless communication systems can be configured to include a series of wireless access points, which can provide coverage for respective locations within the system. Such a network structure is generally referred to as a cellular network structure, and access points and/or the locations they respectively serve in the network are generally referred to as cells.
A mobile device, or user equipment (UE), can discover one or more cells within a wireless communication network and select at least one cell to access to utilize wireless communication services. Cell discovery can include detection of synchronization signals, determination of cell identities, acquisition of system timing, etc. Once one or more cells are discovered, the mobile device can select a cell to access. In one example, the mobile device can evaluate pilot or reference signals from discovered cells to identify a strongest cell, a closest cell, etc. In another example, the mobile device can select a discovered cell associated with an operator through which the mobile device has a service agreement.
Once a cell is selected, the mobile device can initiate random access procedures to access the cell. Random access procedures can be contention-based or contention free. In a contention-based random access attempt, the mobile device selects a random access preamble and transmits a preamble message on resources associated with a random access channel. The mobile device receives a random access response message which can include a timing adjustment, an identifier for the mobile device, an uplink grant for a subsequent message, etc. The mobile device can employ the uplink grant to transmit a message that includes a unique identifier of the mobile device. Subsequently, the mobile device receives a contention resolution message which echoes the unique identifier of the mobile device.